Laser lithotripsy device with suction

ABSTRACT

A medical device is provided which comprises a suction conduit and an energy-transmitting conduit wherein at least some of the transmitted energy is directed to the distal region of the suction conduit. The device may include an optical apparatus for directing the energy. The device has applications in lithotripsy and tissue-removal in a patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the priority to and the benefit of U.S.provisional patent application Ser. No. 60/120,666 filed on Feb. 19,1999, which is incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present invention relates to methods and devices fordestroying and removing unwanted materials such as calculi, deposits andtissues (for example, polyps, tumor cells) from body lumens, and moreparticularly to laser lithotripsy treatment of urinary stones.

BACKGROUND INFORMATION

[0003] Open surgical intervention was once the standard treatment forthe removal of calculi or stones, especially when such calculi aredeposited in a body lumen other than the bladder. But other lessinvasive techniques have emerged as safe and effective alternatives.Lithotripsy, the crushing of stones that develops in the body intofragments that are easier to remove, is one such technique. Lithotripsydevices have been developed which utilize electrohydraulic probes,ultrasonic probes, electromechanical impactors, or a pin driven bycompressed air. These devices typically use percutaneous endoscopictechniques and are configured to be introduced into the body throughsmall puncture sites to avoid open surgical intervention. Focused shockwaves can also be delivered from an external source in a non-invasiveprocedure known as extracorporeal shock wave lithotripsy (ESWL).

[0004] Recently, lasers have been used as an alternative source ofenergy in lithotripsy, especially for the destruction of renal andbilary stones. Lasers are suited for minimally invasive lithotripsybecause the diameter of the laser fiber is small and the aperture of theworking channel can be minimized. An extensive review of the use oflasers for lithotripsy is provided in the book entitled “LaserLithotripsy,” edited by R. Stein, Springer Verlag, 1988. A fiber opticthat travels along the longitudinal axis of a rigid or flexibleendoscope typically transmits the laser beam. Various types of laserlithotripsy systems with a variety of laser sources, including pulseddye laser, alexandrite laser, neodymium laser and holmium laser, havebeen developed.

[0005] A common problem in intracorporeal lithotripsy treatment is thedifficulty in restricting target movement. For example, when usingpulsed lasers such as the holmium yttrium-aluminum-garnet (Ho:YAG)laser, higher frequency pulsation and higher energy in each pulseproduce quicker fragmentation of the stone, but also produce significantstone mobility, which decreases treatment efficiency. Lower frequency topulsation and lower pulse energy may result in less significant stonemobility, but the treatment time will be prolonged. Regardless of energylevel of each emission, stones of smaller sizes present an inherentmobility problem. Incomplete lithotripsy treatment of smaller stones ordebris can leave a nidus for future stone growth.

[0006] Another problem often encountered by a lithotripsy endoscopistinvolves the suction tube that is found in some endoscopes. Such aconduit is generally connected to a pump that produces a vacuum when inoperation and clogging at distal ends by stones and their fragments hasbeen widely reported. See. e.g. U.S. Pat. No. 4,146.019 to Bass et al.Severe clogging may necessitate repeated removal, cleaning andreinsertion of the endoscope during an operation.

SUMMARY OF THE INVENTION

[0007] An object of the present invention is thus to restrict themovement of targets of lithotripsy treatment, especially small stonesand stone fragments. Another object of the invention is to remove stonefragments resulting from a lithotripsy treatment in a more complete andimmediate manner. Yet another object of the invention is to solve theproblem of clogging at the distal region of a suction conduit used inlithotripsy.

[0008] The present invention provides devices and related methods forthe destruction and removal of unwanted materials such as calculi,deposits and tissues (e.g., polyps and tumor cells) from a patient'sbody lumen. The invention achieves these objects by combining a suctionconduit with a high-energy delivery system such that at least some ofthe high energy transmitted is directed to a region near the distal endof the suction conduit. For example, some of the energy can be directedinside, outside, at the face of the tip or a combination thereof. As aresult, the energy destroys materials stuck at the distal end of thesuction conduit and provides the user with a suction device that isequipped with a non-clogging tip.

[0009] The devices of the invention comprises a suction conduitconnected to a pump for suction and a second conduit connected to anenergy source for transmitting high energy. Once the suction conduit isin operation, it keeps stones or stone fragments near its tip,stabilizing the movement of the stone. The second conduit is designed todirect a position of the high energy into, across, and/or outside of thedistal end of the suction conduit and thus onto the stones or stonefragments. The energy fragments, pulverizes or erodes stones, includingthose caught by the force of suction onto the tip of the suctionconduit, into smaller parts or dusts, and the suction conduit caninstantaneously evacuate the stone debris. For example, in a preferredembodiment where Ho:YAG laser is used as the energy source, the laserenergy continues to break down fragments that are still too large toenter the suction conduit while knocking them off the suction tiptemporarily thus preventing clogging of the tip. A portion of the energymay also be directed into a portion of the lumen of the suction conduit,thereby preventing clogging that would have occurred after debrisentered the conduit.

[0010] The devices and methods of the invention take full advantage ofthe suction force in, removing debris instantaneously from the site ofthe treatment, allowing a more complete and speedy treatment. Also, bydirecting a high energy towards the distal region of the suctionconduit, the devices point the energy into a region where targets areaccumulated and relatively immobilized by the suction. The devices andmethods thus offer enhanced treatment efficiency by permitting a morethorough removal of debris and by avoiding operational difficultiesassociated with a clogged suction conduit.

[0011] In one aspect, the devices of the invention can also be equippedwith structures such as barriers or shields in the distal region of thesuction conduit to help block large particles. In another aspect, thedevices of the invention use multiple energy conduits bundled ordispersed in or around the wall of the suction conduit. Yet in anotheraspect, the devices use multiple conduits bearing indicia or markingthat permit their identification during a procedure. In still anotheraspect, the devices of the invention direct energy towards the distalregion of the first suction conduit with or without a separate opticalapparatus such as mirrors, lenses, prisms for example.

[0012] The devices and methods of the invention can be used for theremoval of stones and calcifications throughout the body. First, thedevice is inserted into the body lumen of a patient and the distal endof the suction conduit is positioned near a stone. Then, a high energyis transmitted by the energy conduits and directed to the distal regionof the suction conduit, thereby breaking up stones stuck at the distalregion and removing its fragments through suction.

[0013] The devices can also be utilized for the removal of soft tissuesuch as polyps or tumor cells. For example, the device is first insertedinto the body lumen of a patient and the distal end of the suctionconduit is positioned near the tissue to be removed. Then, a high energyis transmitted by the energy conduits and directed to the distal regionof the suction conduit and thereby shearing off the tissue and removingit through suction. Additionally, the devices can be used for orthopedicapplications and endoscopic applications such as arthroscopy andendoscopic retrograde cholangio-pancreatiography (ERCP).

[0014] The foregoing and other objects, aspects, features, andadvantages of the invention will become more apparent from the followingdescription and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In the drawings, like reference characters generally refer to thesame parts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention.

[0016]FIG. 1A is a perspective view of an embodiment of a medical devicewith two conduits configured in accordance with the subject invention.

[0017]FIG. 1B is a perspective view of an embodiment of a medical devicewith two conduits and an energy-directing apparatus configured inaccordance with the subject invention.

[0018]FIGS. 2A-2D are longitudinal cross-section views of variousembodiments of the distal end of the suction conduit taken along line6-6 in FIG. 1A.

[0019]FIG. 2E is a perspective view of an embodiment of a suctionconduit with a mesh-cap in accordance with the subject invention.

[0020]FIG. 2F is a perspective view of an embodiment of a device with acurved barrier at the distal end of the suction conduit in accordancewith the subject of the invention.

[0021]FIG. 3A is a perspective view of an embodiment of a device with anenergy-transmitting conduit that has endoscopically discernable externalmarkings in accordance with the invention.

[0022]FIG. 3B is a perspective view of an embodiment of anenergy-transmitting conduit with an alternative marking pattern inaccordance with the invention.

[0023]FIG. 3C is an elevated perspective view of an embodiment of amedical device with a twisted bundle of laser fibers in accordance withthe invention.

[0024]FIG. 4 is a partly cross-sectional view of an embodiment of alaser lithotripsy device with housing configured in according with theinvention.

[0025]FIG. 5A is a perspective view of an embodiment of a device with amulti-channel housing configured in accordance with the invention.

[0026]FIG. 5B is a longitudinal cross-section view of the device in FIG.5A taken along line 6-6 in FIG. 5A.

[0027]FIGS. 6A-6C are schematic views of modified distal ends of laserfibers in accordance with the invention.

[0028]FIG. 7A is a schematic longitudinal cross-section view of anangled tip of a laser fiber manufactured by etching.

[0029]FIG. 7B is a side view of laser fiber tip applied with areflective coating in accordance with the invention.

[0030]FIGS. 8A-8B are partly cross-sectional views of embodiments of alaser lithotripsy device with an optical apparatus configured inaccordance with the invention.

[0031]FIG. 9 is a schematic longitudinal cross-section view of anembodiment of the invention with an optical apparatus.

[0032]FIG. 10A is a perspective view of an embodiment of a device withmultiple channels for laser fibers surrounding a suction conduit.

[0033]FIG. 10B is a radial cross-section view of the device in FIG. 10Ataken along line 6-6 in FIG. 10A.

[0034]FIG. 11 is a schematic view of a tissue-removing device with anoptical apparatus in accordance with an embodiment of the invention.

DESCRIPTION

[0035] Definition

[0036] Distal region: a region near or around, both inside and outsideand including an end that is farther away from the origin of attachment.

[0037] Conduit: a channel or a tubing for conveying energy or matter.

[0038] Detailed Description

[0039] The devices and methods of the present invention combine anenergy-transmitting means with a suction means to enhance the efficiencyof material removal from a body lumen. In doing so, they solve both theproblem of calculi mobility and clogging at the distal region of asuction means used in such medical procedures. The devices comprise atleast a Suction conduit and a high-energy conduit, and the energytransmitted is at least partly directed to the distal region of thesuction conduit. Other elements such as viewing instruments, anillumination means or an irrigation conduit can be further combined withthese elements.

[0040] Referring to FIGS. 1A and 1B, an embodiment of the devices of thepresent invention comprises a suction conduit 1 and anenergy-transmitting conduit 2. The suction conduit 1 is connected at itsproximal end to a pump 3 that creates a vacuum. The energy-transmittingconduit 2 is connected at its proximal end to a high-energy source 4 andtransmits and directs the high energy to the distal region 5 of thesuction conduit 1. The suction conduit 1 and the energy-transmittingconduit 2 can be co-extruded, otherwise attached to each other or remainseparate. Further, one can be inside the other. Directing the highenergy to the distal region 5 may be achieved without additionalapparatuses, as in FIG. 1A, or may involve at least one additionaloptical apparatus 30, as illustrated in FIG. 1B.

[0041] The suction conduit can be made of a variety of flexible or rigidmaterials or a combination of both, such as stainless steel or plastics.To improve conduit's resistance against kink-formation or againstcollapse under vacuum pressure, and to preserve flexibility in themeantime, either or both of the conduits can be braided or wound withfibers made of materials such as metals or plastics. The conduit mayhave coatings on its inside or outside for various purposes, forexample, for protection against corrosion by body fluids or forinsulation against the high energy emitted towards its distal region. Itcan be of any dimension convenient for its intended use. It can befurther inside a housing or a sheath. It can house theenergy-transmitting conduit by itself. It can be fixedly integrated intoa larger instrument or slidingly inserted into the instrument such asdescribed in U.S. Pat. No. 4,146,019 to Bass et al., incorporated hereinby reference. A stainless steel conduit can be passed through a rigidendoscope. A suction conduit made of a flexible material (such asplastic or a super elastic alloy such as Nitinol) can be passed througha flexible endoscope. A preferred embodiment is an elongatedpolypropylene tubing of ⅛ inch outside diameter that can be used in anendoscope. The devices of the invention may include multiple suctionconduits.

[0042] The proximal end of the suction conduit is connected to a pump 3,which provides a vacuum when operated. A control mechanism can befurther added to the system to modulate the intensity of the vacuum.

[0043] The distal end 8 of the suction conduit 1 may assume any shapeconvenient for its intended use. For example, a suction conduit 1 mayhave a planar face 7 at its distal end, as depicted in FIGS. 2A and 2B.In FIG. 2B, the face 7 of the distal end is at a beveled angle to theconduit 1's longitudinal axis. The face 7 may also assume a curved form,for example, ellipsoidal as shown in FIG. 2C. Alternatively, as shown inFIG. 2D, the suction conduit 1's distal end may contain at least oneside aperture 39. Configurations of the distal end such as those inFIGS. 2B-2D will effectively provide at least one side opening,resulting in direct flow 41 from both the side and the front of thesuction conduit 1. Where the devices of the invention are used to removematerials from the walls of a body lumen, embodiments having sideopenings are preferable, because these side openings readily accesstarget materials, avoiding having to bend the tip. Furthermore, thedistal end of the suction conduit can be made of a material differentfrom the body of the conduit. For example, one might want to make thedistal end with a more heat-resistant material to withstand high energydirected to it. It may also be desirable to use a more impact-resistantmaterial to withstand the initial impact from stones drawn by thesuction force.

[0044] Additional structures at the distal region may help preventclogging of the suction conduit. For example, a filter, a screen, amesh, a shield or other barriers can be molded onto or otherwiseattached to the distal region of the suction conduit. Referring to FIG.2E, a mesh 9 is attached onto the distal end 8 of the suction conduit 1.The mesh 9 may be placed further inside or outside the distal end 8.Alternatively, several such barriers may be placed along the length ofthe suction conduit 1.

[0045]FIG. 2F shows an example of a barrier positioned outside thedistal end of the suction conduit. A channel 12 enclosing anenergy-transmitting conduit (a laser fiber 22 in this case) is inserteddirectly in the suction conduit 1. The distal end of the channel 12 is acurved barrier 25, forming a cap over the distal end 8 of the suctionconduit 1, and leaving a gap 33 preferably for about 1-10 mm. The gap 33is set to admit stone fragments having a size smaller than the suctionconduit 1 or than the space between the suction conduit 1 and thechannel 12. The distal end 28 of the laser fiber 22 is disposed in thedistal region of the channel 12. In the particular embodiment in FIG.2F, the end 28 is outside the barrier 25, but it can be flush with orreceded closely inside the barrier 25. Also, there may be multiple laserfibers enclosed in the channel 12. The barrier 25 can be made of anysolid material that can withstand the energy emitted from the distal end28 and be of sufficient hardness to withstand the impact of stones drawnbys the suction force. The barrier 25 is preferably made oflight-transmitting materials such as glass or quartz so that it acts asa lens for the laser emitted from the tip 28. The tip 28 can be inside,flush with or outside the barrier 25 and it may be modified, as detailedin later sections, to diffuse or deflect light side-wise or backward.Once the pump 3 is in use, fluid flow will direct mobile particles, suchas stone fragments 39, towards the periphery of the barrier 25 and awayfrom the fiber tip 28. As a result, particles must go through the gap 33between the barrier 25 and the distal end 8 to enter the suction conduit1. The size of barrier 25 can vary as long as the gap 33 is narrowenough to effectively prevent clogging of the suction conduit. Inembodiments where the energy-transmitting conduit is closely recededinside the barrier 25, the large surface area of the barrier exposed tothe flow of liquid will help cooling the barrier off rapidly.

[0046] The invention contemplates energy sources known to one ofordinary skills in the medical profession for fragmenting, coagulating,or vaporizing various unwanted materials from a body lumen. Such anenergy could be mechanical, electric, chemical or a combination thereof.The energy may be delivered in the form of heat, electric current,sparks, laser radiation, radio frequency (RF), ultrasonic wave,mechanical vibrations, ballistic impact, hydraulic shock or chemicalcorrosives. These techniques are well known in the art and are describedin publications, such as U.S. Pat. Nos. 5,281,231 to Rosen et al. and5,443,470 to Stern et al., and “The Swiss Lithoclast: a New Device forIntracorporcal Lithotripsy” by Denstedt et al. in September 1992's TheJournal of Urology; the entirety of all three are incorporated herein byreference.

[0047] In a preferred embodiment, the energy is laser energy with awavelength that is highly absorbable in a liquid medium. Typically suchwavelength regions are the mid-infrared portion of the spectrum fromabout 1.4 to about 11 micrometers and in the ultraviolet pollution of190-350 nanometers. Lasers which can be utilized in the presentinvention are thulium (Th), holmium (Ho), Erbium:yttrium-aluminum-garnet(Er:YAG), HF, DF, CO, and CO₂ in the mid-infrared region, and excimerlasers in the ultraviolet region.

[0048] In a preferred embodiment, Ho:YAG laser is utilized. The holmiumlaser is useful because it produces fine dust and small debris ratherthan stone chunks, and thus facilitates removal of the stone. The Ho:YAGlaser can be used not only for the treatment of calculus, but also forsoft tissue. The holmium laser energy is typically transmitted through afiber. When a holmium laser, after travelling the length of the fiber,is fired into a liquid medium the laser energy produces a vaporizationbubble.

[0049] The Ho:YAG laser produces light at a wavelength of 2.0 to 2.1microns, depending on the precise formulation of the holmium rod, in apulsed fashion. In one configuration, the laser produces light at awavelength of 2.09 microns. These wavelengths are well absorbed by waterand other liquid mediums. All stones in a body lumen (including cystinecalculi) absorb this wavelength well, regardless of the stone colorbecause of the water in the stone and on the stone surface. This is amajor improvement over previous user sources such as pulsed dye laser,the effectiveness of which depends on pigmentation on the target. Thepulse duration of Ho:YAG laser also produces photoacoustic effects thataid stone fragmentation. In a particular embodiment, the Sharplan 2025Holmium:YAG Surgical Laser is utilized as a source of laser energy.

[0050] In suitable laser systems, the energy of each pulse and thepulsation frequency can be varied. Generally, high frequency ofpulsation and high energy produce a quick fragmentation but alsoproduces a significant amount of stone mobility. Lower frequency ofpulsation and lower energy is more precise but the overall treatmenttime is prolonged. High frequency of pulsation and high energy can beused by the devices of the present invention because the suction forcelimits stone movement. By combining suction with a laser delivery systemin accordance with the methods of the invention, the overall efficiencyof treatment is improved. In particular, higher powers, more efficientlasers, such as holmium lasers, can be used even when small stones arepresent because the suction helps keep the small stones in the path ofthe laser. Preferably, the energy levels used as between about 0.2 and2.8 Joules per pulse and the frequency is between about 5 and 20 Hertz.Typical pulse durations are about 200-400 microseconds. Preferably, thepulse duration is 250 microseconds.

[0051] Referring again to FIGS. 1A and 1B, a high-energy source 4 isconnected to the proximal end of the energy-transmitting conduit 2. Thisconduit 2 should be made of a material that is suitable for thetransmission of the energy used in the device and variables of itsdimension (such as length, diameter and shape) should be suitable forthe intended use of the device. It can be further inside a housing or asheath, such as the suction conduit itself. The invention can have morethan one conduit transmitting the high energy. Some or all of them canbe fixedly integrated into a larger instrument or slidingly insertedinto an instrument.

[0052] In a preferred embodiment, this energy-transmitting conduit is alow density, optical quartz fiber that can be used to transmit laserenergy. Generally, the laser fiber extends from about 50 to 500 cm.Preferably, the laser fiber extends from about 80 to 100 cm. Thesefibers range in their core size from about 200 to 1000 microns.Preferably the core size of the laser fiber is between 300 and 550microns.

[0053] In another embodiment, the medical device comprises a pluralityof mobile components within a housing, and at least one of the mobilecomponents has a discernable pattern of indicia disposed on the outersurface of its distal region. The plurality of mobile components may beat least two of any components of a medical device used in a body lumen,including but not limited to, laser fibers, fiber optics, catheters andguidewires.

[0054] For example, in FIGS. 3A and 3B, the energy-transmitting conduit2 is a laser fiber jacketed with a pattern of indicia 23 that aidsdetection of its movement inside a body lumen through a viewinginstrument. An example of a viewing instrument is an endoscope thatcontains a fiber optic illumination source and a fiber optic lens forviewing. Typically, the scope view 29 shows a small section of the laserfiber near the fiber's distal end. However, commercially available laserfibers generally have no distinguishing marking on the outside they aregenerally jacketed in a monochromatic (e.g., black) and glossy plasticwrapping. One aspect of the invention is to provide discernable markingsor indicia 23 for the energy-transmitting conduit and other mobilecomponents in the device. The markings only needs to appear on thesection that is to be seen through the viewing instrument in the case ofan endoscope, the distal region of the fibre visible under the scopeview 29. The spiral and checkered patterns, as shown in FIGS. 3A and 3Brespectively, are examples of preferred embodiments because thesepatterns indicate, in the scope view 29, conduit movements both alongand about the longitudinal axis. Further, the energy-transmittingconduit and any tubular components (such as a guidewire) viewablethrough the endoscope should have different markings for the user totell them apart. This can be accomplished through different colors orpatterns. This inventive aspect contributes to the overall goal of theinvention when movements of the components are desired for operating thedevice or the movements actually take place, and where direct visualmonitoring of such movements will aid the operation of the device.

[0055] To make components of the devices further discernable whencombined with a viewing instrument such as an endoscope, anon-reflective or low-reflective coating as a pattern of indicia can beapplied to these conduits to soften light reflected from them. In anendoscope with a means of illumination, the light is often so intensethat the user finds it difficult to view through the viewing instrument.A coating that reduces light reflection from the laser fiber jacket, forinstance, will solve that problem.

[0056] Referring to FIG. 3C, multiple laser fibers 13-15 are housed in achannel 12 of a larger instrument, such as an endoscope and the arrangedfibers provide markings, as a whole, that are endoscopicallydiscernable. There can be a variety of ways of bundling multipleconduits, such, as spirally twisting the bundle (as in FIG. 3C),braiding into a bundle, gluing, tying or fitting tightly into a channelof a housing. Twisting, braiding or otherwise tightening the associationof multiple fibers retains much of the flexibility of individual fibers.It is easier to move bundled fibers than unbundled ones inside ahousing, whether along or about the housing's longitudinal axis. In apreferred embodiment, each of the three fibers is jacketed in a sleeveof a different color, forming an overall spiral pattern when insertedinto an endoscope. The same principle applies to other numbers ofenergy-transmitting conduits as long as endoscopically discernablepatterns are provided by the overall bundle.

[0057] Directing at least a portion of the energy emitted towards thedistal region of the suction conduit can be accomplished with the laserfiber itself as an integral optical feature or with a separate opticalapparatus.

[0058] For example, spatial relationship between the two conduits is onesolution. In FIG. 4, a suction conduit, channel 11, is integral to aninstrument 10 that houses a laser-transmitting fiber 22 inside its otherchannel 12. A divider 17 having a distal end 20 partly separates channel11 from channel 12. The housing 10 has a distal end 16 that comes intocontact with a stone 34 that is to be removed. The laser fiber 22 isconnected to a laser source 24 at its proximal end 26. The laser fiber22's distal tip 28 is close to both the distal end 16 of the housing 10and the distal end 20 of the divider 17, so that stones caught at eitherof the distal ends 16 and 20 can be exposed to laser radiation emittedfrom tip 28.

[0059] In the particular embodiment shown in FIG. 4, both the laserfiber's distal tip 28 and the divider 17's distal end 20 are disposedwithin the distal end 16 of the housing 10. This illustration is notmeant to put any structural limit on the devices of the invention. Inother embodiments, both or either of the distal tip 28 and the distalend 20 may be flush with the distal end 16 of the housing or may extendbeyond it so long as at least a portion of the laser radiation from tip28 can effectively fragment a stone caught at the distal region of thesuction conduit 11.

[0060] In FIGS. 5A-5B, the divider 17 is positioned so that itfacilitates the placement of a laser fiber 22 at a beveled angle withthe longitudinal axis of the housing 10, thereby directing laserradiation emitted from tip 28 of the energy-transmitting conduit 22towards the distal region of suction conduit 11. Furthermore, becausethe diameter of the suction conduit increases towards its proximal end,clogging along the body of the suction conduit is prevented.

[0061] In other embodiments, a portion of the energy emitted from thetip 28 maybe directed towards the distal end of the suction conduitthrough modifications to the energy-transmitting conduit. For example,the distal end of a typical, commercially available laser fiber can bemodified so that a larger surface area will be radiated by the laser.FIGS. 6A-6C disclose examples of modifications with various opticallenses disposed at the laser fiber tips to diffuse the laser energy.These optical lenses are easily manufactured by removing the plasticjacket from the distal region of the fiber, then using a torch tothermally heating up the remaining optical core at the distal end,including its usual silicon clad. The tip will melt, and after coolingoff in room temperature, will form a ball as shown in FIG. 6A. If themolten tip is pressed against a nonporous, flat surface at a rightangle, a flat-end tip resembling that shown in FIG. 6B will result.Further pressing the same flat surface on the lateral sides of the tipwill result in an extended tip resembling what is shown in FIG. 6C. Anextended tip, of about 5 mm, is especially advantageous for continueduse of the same laser fiber.

[0062] Other means of affecting the direction of laser path withoutresorting to additional apparatus include etching near the distal end ofthe energy-transmitting conduit or bending the distal tip forside-firing (described in U.S. Pat. No. 5,416,878 and incorporatedherein by reference). Cutting at multiple spots in the distal region ofa laser fiber results in light emission along the distal region, inaddition to the distal end. FIG. 7A provides a specific example ofetching, where the distal end 28 of a laser fiber is cut so that anangled tip is formed. In a schematically depicted laser fiber 22, laserlight 42 travels along the optical core 37 via bouncing between thesilicon clad 36, which is further wrapped in a plastic jacket 35. Asshown here, because in the angled tip, one side of the fiber is longerthan the other, some of the laser light 42 will be deflected side-wiseonce it reaches the end of the optical core 37.

[0063] Reflective coatings on the laser fiber may also be used to affectthe laser path. Referring to FIG. 7B, a portion of the distal region ofthe laser fiber 22 has been stripped of the plastic jacket 35 and thesilicon clad 36 (therefore “unclad”), and at least one layer ofreflective coating 50 has been selectively applied, to the remainingunclad optical core, including the distal face 48. The reflectivecoating 50 is not applied to certain areas on the unclad optical coreso..that reflected laser light can “escape” from these areas and reach atarget such as the distal region of the suction conduit. Depending onthe effectiveness of the coatings, however, some of the light mightstill go through the coated areas.

[0064] An optic, separate from the energy-transmitting conduit may beplaced near the distal end of the energy-transmitting or of the suctionconduit to help direct the emitted energy towards the distal region ofthe suction conduit. In preferred embodiments where the energy is aHo:YAG laser, the devices of the invention include an optical apparatus.

[0065] Several optics known in the art that guide laser emission to acertain area can be used in the invention. They can be a surface, aseries of surfaces, a medium, a series of media, or a combination of anyof the above that alters the path of light. For example, a lightdiffusing apparatus is described in U.S. Pat. No. 5,151,096 to Khoury,incorporated herein by reference. Examples of other optics include andare not limited to a lens, a mirror (U.S Pat. No. 4,445,892). a seriesof mirrors (U.S. Pat. No. 5,496,306), a prism (U.S. Pat. No. 5,496,309)and a parabolic reflector (U.S. Pat. No. 4,672,961) (the disclosure ofthese patents are incorporated herein by reference).

[0066] In the present invention, the optical apparatus is operativelyassociated with the two conduits to help direct laser light from thedistal end of the energy-transmitting conduit toward the distal regionof the suction conduit. In FIGS. 8A-8B, an embodiment has an opticalapparatus 30 coupled near the distal end 16 of a housing similar to thatshown in FIG. 4. In the embodiment shown in FIG. 8A, the divider 17 isreceded proximal to the optical apparatus 30, which, in turn, is recededinside the distal end 16 of the housing 10. In the embodiment shown inFIG. 8B, the divider 17 extends all the way to the distal end 16 of thehousing 10, and the optical apparatus 30 is also positioned moreoutward. The angle of the optical apparatus 30 may be varied to direct alarger portion of the energy emitted from the laser fiber 22 inside,across or outside the face of the distal end 16.

[0067] The optical apparatus 30 can be made of a variety of materialsthat are known in the art to be suitable for reflecting, deflecting,diffusing, or refracting the particular energy emitted from the tip 28of the laser fiber. Such materials include, but are not limited to,crystal, quartz, garnet, stainless steel or gold. The optical apparatus30 may assume a variety of configurations such as a planar surface, anellipsoidal surface, a convex surface or a pyramid.

[0068] The device with an optical apparatus may utilize Ho:YAG laserenergy which produces a vaporization bubble, a semi-circle of energy,extending from the tip of a firing laser fiber to a target stone whenthe laser tip is immersed in liquid. While the body lumen where thedevice is operating generally has plenty of water, a separate irrigationconduit can be added to the device to ensure that the tip is constantlyimmersed in water. The optical apparatus 30 in FIGS. 8A and 8b directsthe vaporization bubble (not shown) into the distal region of thesuction conduit 11 and onto the stone 34. A shock-wave is then producedby the collapse of the vaporization bubble at the interface betweenwater and the stone.

[0069] Referring to FIG. 9, another preferred embodiment of the devicehas a reflective surface 31 (a mirror, for example) fixedly attached tothe distal end of an energy-transmitting conduit (a laser fiber 22 inthis case). A housing 32 preferably made with a light-transmitting hardmaterial such as quartz, fixedly encloses the distal region of the laserfiber 22. The housing 32 protects the laser fiber 22 and acts as a lensfor the laser. Laser energy emitted from distal end 18 of fiber 22 isreflected by the reflective surface 31 and travels through the housing32 to the distal region of the suction conduit 11. Alternatively, thehousing can be made of an opaque material with an opening for the laserlight to travel to the distal region 5 of the suction conduit 11.

[0070] Different embodiments and various features of the invention canbe combined in the same device in accordance with the invention. Anembodiment may contain multiple optical features and any of the distalbarriers mentioned earlier. For example, multiple laser fibers modifiedwith an optical lens-tip as illustrated in FIGS. 6A-6C, and braidedtogether as shown in FIG. 3, may be disposed inside the distal end ofthe barrier 25 of the device shown in FIG. 2F—the barrier 25 is made ofglass, quartz or sapphire and serves as a lens at the same time.

[0071] There are several ways to direct a larger portion of emittedenergy towards the distal region 5 of the suction conduit. In oneembodiment, the diameter of the energy-transmitting conduit isincreased. In other embodiments, an optical apparatus is added.Alternatively, more energy-transmitting conduits can be incorporatedinto the device. In a preferred embodiment, these conduits areintertwined and bundled before being incorporated into the device.Again, all these measures can be implemented in the same embodiment. Inanother preferred embodiment shown in FIGS. 10A and 10B, multipleenergy-transmitting conduits such as multiple laser fibers 22 are housedin multiple channels of a housing 10. In this particular embodiment,these channels surround the suction conduit 1. Some of the channels mayenclose other functional components. As shown in FIGS. 10A and 10B, oneof the channels is an irrigation channel 45, which transfers a coolingagent from an irrigation source 38. Another channel contains a guidewire46. Two other channels each contain a pullwire 47. A pullwire is a wirefixedly attached to the distal end 16 of an endoscopic instrument and auser can deflect the distal end 16 upon pulling such a wire.

[0072] The devices of the invention may be combined with, orincorporated into, a catheter, an endoscope or other medical devicescustomarily used for the destruction and removal of unwanted materialsfrom body lumens. Preferably, when incorporated into an endoscope, thedevices of the invention combine a guidewire, a fiber optic forillumination, a fiber optic or visualization, a conduit for irrigationand pullwires for active deflection.

[0073] The devices of the invention have applications in lithotripsy. Inthe methods of the invention, the device 10 shown in FIGS. 10A and 10B,is placed with its distal end 16 in the vicinity of a calculus. Uponapplication of vacuum in the suction conduit 1, the suction pulls largestone fragments toward the distal end 16 of the housing. 10. The lasersystem 24 delivers laser energy to the tip of the laser fibers 22. Thelaser energy is then emitted from the tip of the laser fibers 22. Thelaser energy may be in the form of a vaporization bubble. Optionally, anoptical apparatus further directs the laser energy released from thelaser fiber 22 into, across the face of, and/or outside of the suctionconduit 1 and onto a stone. The laser energy impacts the stone caught bythe suction at the distal region of the suction conduit 1, causing it tobe propelled off the tip and fragmented into smaller stone fragments.The suction then pulls the smaller fragments back into the distal regionof the conduit 1. Fragments small enough will enter the suction conduitand be evacuated from the treatment site. Large fragments still be heldat the distal end of the suction conduit. The laser energy impacts thestone fragment causing it to be propelled off the tip and fragment intoeven smaller fragments. This process is repeated until the stonefragments are small enough to be all evacuated through the suctionconduit 1. Directing at least some of the laser energy into the suctionconduit 1 keeps, the conduit clear of obstruction.

[0074] In addition to removing stones, the devices of the invention canbe utilized to remove soft tissue, for example, to facilitate thetreatment of tumors or soft growths in both the gastrourinary (GU) andthe gastrointestinal (GI) tract. Specifically, the devices can beutilized to shear off and evacuate soft tissue such as polyps. Papillarylesions can be fragmented and evacuated while the base of the lesion iscoagulated.

[0075] In one embodiment for treatment of soft tissue, illustrated inFIG. 11, the laser lithotripsy device is modified to facilitate theremoval of polyps. The tip 28 of the laser fiber 22 and the opticalapparatus 30 attached to the distal end 16 are both disposed within thechannel 12 about 2 millimeters from the distal end 16. Soft tissue 40such as a polyp or tumor is sucked into the suction channel 11, issheared off by the laser energy emitted by the laser fiber 22, and thenis evacuated by the suction. The angle of the optical apparatus 30 maybe varied to change the direction of the laser energy emitted from thetip 28. The laser lithotripsy device with an angled laser fiber tip butwithout a separate optical apparatus may also be modified to accommodatesoft tissue by moving the tip 28 of the laser fiber 22 further withinthe channel 12 several millimeters from the distal end 16.Alternatively, the device can be equipped with fluoroscopic guidance sothat the laser can be directed onto the polyp or tumor.

[0076] Variations, modifications, and other implementations of what isdescribed herein will occur to those of ordinary skill in the artwithout departing front the spirit and the scope of the invention asclaimed. Accordingly, the invention is to be defined not by thepreceding, illustrative description but instead by the spirit and scopeof the following claims.

1. A medical device, comprising: a first conduit having a proximal endconnected to a pump which provides suction at a distal region of thefirst conduit; and a second conduit having a proximal end connected to ahigh energy source and which transmits a high energy to a distal end;wherein the distal end of the second conduit directs at least a portionof the high energy emitted to at least a portion of the distal region ofthe first conduit. 2.-34. (Canceled)